Hi, I have a system with secondary SATA SSD (OCZ Saber 1000 480GB) which is readable in Windows. The drive capacity shown when probed by the kernel during boot is 937703088 = 0x37E436B0 sectors. The drive seems to be failing the command issued by libata to read its last 8 sectors. After reporting ata8.00: exception Emask 0x0 SAct 0x40 SErr 0x0 action 0x6 frozen ata8.00: failed command: READ FPDMA QUEUED ata8.00: cmd 60/08:30:a8:36:e4/00:00:37:00:00/40 tag 6 ncq dma 4096 in it tries resetting the link several times and eventually gives up. In this state, while the block device and sg device (/dev/sda and /dev/sg5) are still present, any attempt to e.g. issue INQUIRY or READ CAPACITY fails, along with data access commands like READ and WRITE, meaning the drive is inaccessible in Linux. I'm not sure whether the drive itself locks up after receiving that read command, or whether libata is giving up too soon, or whether that error could just be ignored. Is there any way to tell libata to avoid issuing the initial end-of-drive read command? Or is that read issued by the block layer? [ 1.499334] libata version 3.00 loaded. [ 1.505518] scsi host0: ata_generic [ 1.505703] scsi host2: ata_generic [ 1.516083] ata8: SATA max UDMA/133 abar m2048@0xf7f12000 port 0xf7f12180 irq 41 [ 1.830511] ata8: SATA link up 6.0 Gbps (SStatus 133 SControl 300) [ 1.830975] ata8.00: ATA-8: OCZ-SABER1000, 1.01, max UDMA/133 [ 1.830978] ata8.00: 937703088 sectors, multi 1: LBA48 NCQ (depth 32), AA [ 1.836358] ata8.00: configured for UDMA/133 [ 33.943503] ata8.00: exception Emask 0x0 SAct 0x40 SErr 0x0 action 0x6 frozen [ 33.943585] ata8.00: failed command: READ FPDMA QUEUED [ 33.943631] ata8.00: cmd 60/08:30:a8:36:e4/00:00:37:00:00/40 tag 6 ncq dma 4096 in [ 33.943735] ata8.00: status: { DRDY } [ 33.943768] ata8: hard resetting link [ 39.295447] ata8: link is slow to respond, please be patient (ready=0) [ 43.975468] ata8: COMRESET failed (errno=-16) [ 43.975531] ata8: hard resetting link [ 49.327467] ata8: link is slow to respond, please be patient (ready=0) [ 54.007448] ata8: COMRESET failed (errno=-16) [ 54.007512] ata8: hard resetting link [ 59.359466] ata8: link is slow to respond, please be patient (ready=0) [ 89.059463] ata8: COMRESET failed (errno=-16) [ 89.059532] ata8: limiting SATA link speed to 3.0 Gbps [ 89.059533] ata8: hard resetting link [ 94.111441] ata8: COMRESET failed (errno=-16) [ 94.111508] ata8: reset failed, giving up [ 94.111545] ata8.00: disabled [ 94.111668] ata8: EH complete